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How many types of graphite materials exist?

Inwin-style News 2021-04-25
Graphite materials can be divided into two types: natural graphite and artificial graphite
Type 1: Natural graphite
In nature, graphite mainly exists in the form of flakes and blocks, which are called flake graphite and block graphite, respectively. Some are also in the form of extremely fine powder, called amorphous graphite. This is the habitual name for this kind of fine graphite. Natural graphite is the same as natural mica. Even though the particle size is very fine, it always maintains a very high crystalline state under the microscope, so it is often called cryptocrystalline graphite. Scaly graphite mainly exists in metamorphic rocks such as gneiss or marble, and is formed by the metamorphism of carbon-rich sediments. Lump graphite mainly exists in stratified rocks formed by solidification of magma, such as limestone and slate. It is generally considered to be coal that exists in crevices and caves formed by ore vein stratified rocks. It is transferred under high temperature and hydrothermal conditions. The crystal is formed. The micro- and fine-grained graphite in metamorphic rocks is also formed by the metamorphism of carbon-rich sediments.
Graphite crystals are formed by stacking layer-shaped molecules. The force within the layer is very strong, but the force between the layers is very weak. Therefore, many physical and chemical properties of graphite have significant anisotropy. In the direction parallel to the layer, there is a complete cleavage and easy to slide between the layers, so the graphite is soft and is a good solid lubricant. The π-bonded electrons between the graphite layers can flow freely along the plane direction, which makes the graphite have metallic luster and good electrical and thermal conductivity. The conductivity of graphite in the plane direction is 100 times that of the vertical direction. In addition, graphite crystals also have high temperature stability (especially thermal shock resistance) and good corrosion resistance.

Type 2: Artificial graphite
Artificial graphite 0.0 is to process easily graphitized materials under high temperature and other conditions to form a regular graphitized sheet structure. The most common artificial graphite is shaped graphite. By using pitch coke, petroleum coke and natural flake graphite as raw materials, it is processed through material selection, calcination, molding, roasting and other processes, and finally it is processed by lathing, grinding and other mechanical processing to become what is needed specification. The specific process flow of artificial graphite at the site is as follows:
(1) Material selection.
The main raw materials of graphite are: petroleum coke, pitch coke, anthracite, graphite powder, etc., according to the use and performance requirements of graphite products, make appropriate selection and coordination.
(2) Calcining.
The calcination of the raw materials is heat-treated in the absence of air, the purpose is to drive out the volatiles and moisture in the raw materials. Calcination results: the volatile content is greatly reduced; the volume shrinks, the porosity decreases, and the density increases; the electrical conductivity and thermal conductivity increase; and the oxidation resistance is improved.
(3) Forming.
The calcined raw materials are crushed, sieved, mixed according to a certain proportion, and then a certain proportion of binding agent (pitch coke, etc.) is added, and the mixture is uniformly mixed and formed. There are two molding methods, one is extrusion; the other is molding.
(4) Roasting.
The formed green body should be roasted in a roasting furnace. The purpose of the graphite production process is to form coke between the magnetic powder particles and connect them closely to form a whole with certain mechanical strength and physical and chemical properties. As the firing process progresses, the volume of the product shrinks, its density is higher, the resistivity is significantly reduced, and the mechanical strength is improved.

The price of natural flake graphite powder
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years experience in providing super high-quality chemicals and graphite powder. As a leading nanotechnology development and powder manufacturer, Luoyang Tongrun dominates the market. Our professional work team provides perfect solutions to help improve the efficiency of various industries, create value, and easily cope with various challenges. If you are looking for natural flake graphite powder, please send an email to: [email protected].
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